package cn.pangza.web.utils;

import java.util.concurrent.*;

public class Threads {


    /**
     * sleep等待,单位为毫秒
     */
    public static void sleep(long milliseconds) {
        try {
            Thread.sleep(milliseconds);
        } catch (InterruptedException e) {
            return;
        }
    }

    /**
     * 停止线程池
     * 先使用 shutdown, 停止接收新任务并尝试完成所有已存在的任务
     * 如果超时，则调用 shutdownNow, 取消在 workQueue 中的等待任务,并中断所有阻塞函数
     * 如果仍然超时，则强制退出
     * 另对在shutdown时线程本身被调用中断做了处理.
     * */
    public static void shutdownAndAwaitTermination(ExecutorService pool) {
        if(pool != null && !pool.isShutdown()) {
            pool.shutdown();
            try {
                if(pool.awaitTermination(120, TimeUnit.SECONDS)) {
                    pool.shutdownNow();
                    if(pool.awaitTermination(120, TimeUnit.SECONDS)) {
                        System.out.println("Pool did not terminate");
                    }
                }
            } catch (InterruptedException e) {
                pool.shutdownNow();
                Thread.currentThread().interrupt();
            }
        }

    }

    /**
     * 打印线程异常信息
     * */
    public static void printException(Runnable r, Throwable t) {
        if (t == null && r instanceof Future<?>) {
            try {
                Future<?> future = (Future<?>) r;
                if (future.isDone()) {
                    future.get();
                }
            } catch (CancellationException ce) {
                t = ce;
            } catch (ExecutionException ee) {
                t = ee.getCause();
            } catch (InterruptedException ie) {
                Thread.currentThread().interrupt();
            }
        }
        if (t != null) {
            System.out.println(t.getMessage() + "        " + t);
        }
    }

}
